Process of protecting articles from corrosion



Patented Feb. 1, 1 35" UNITED STATES PATIENT ol-"rlca WILLIAM S. CALCOTT, OF PINKS GROVE, NEW JERSEY, ALBERT 5. mm, OF m IINGTON, DELAWARE, AND IBEDEBICK B. DOWNING, 0F CABNEYS POINT, m

JERSEY, ASSIGNOBS T0 E. I. DU PORT DE HOURS 0; COMPANY, OF WILMING'ION, DELAWARE, A OOH-PORTION OI DELAWARE P300388 0! PROTECTING ARTICLES FROM CORROSION This invention relates to the art of coating compositions'and more particularly to a process of protectin articles from corrosion by coating them wit a film containing the -reaction product of sulfur chloride and a liquid acetylene polymer.

nrated hydrocarbons 0 'weight are formed and may 1 Prior art lt is known that by passin acet lene into a mixture of ammonium .c lori e, water,

cuprous chloride and co per wder, unsathi er molecular separated by distilling them from the catalyst mixture. The water driven over during the'distillation process is returned to the catalystmixture which is then ready for retreatment with acetylene. The major product is a low boiling (EEO- 0.) highly unsaturated oil, called divinylacetylene and having most probably the empirical formula C.H., but there is also produced at the same time a substantial quantity of 'other polymerizable polymers of acetylene. Among these may be mentioned a polymer having most probably the empirical formula C,,H and,therefore, a tetramer of acetylene, and a olynier believed to have the formula C,H,. ese products may be roughly separated b distillation, and when spread upon a sur ace exposed to'the air yield a dry resistant film.

Further, it has been shown that the mixture obtained as above, or the separated constituents thereof, under the influence of heat or by aging at ordinary temperatures, in the resence of air, further p0 ymerize successively to an oily, then to a elatinous, then I 171111018011 filed September I1, 1m. Serial H0. 884,377.

It will be understood that these succesive polymerization. products consist of a mixture of volatile and non-volatile compounds in various stages of polymerization,-which com unds ma be only roughly separated by issolving, ut may be separated by distillation. When the lymerization is carmed. only through the inital stages, by heating until an oily liquid is obtained, and the resulting product subjected to distillation to remove the unpolymerized fraction remainmg therein, the non-volatile residue has the general properties of a bodied dryin oil.

The use of such drying oils as a -for a coating composition is also known. When so employed, as has been shown in a copendmg application, the flexibility of the thetic oil may be increased by the addition of rubber softeners and the viscosity may be increased by the addition of synthetic resins,

such as meta styrene, or other viscous filmforming material which is. compatible with the drying oil. On the other hand, the viscosity may be decreased by dilution with solvents such as xylene, acetone or but 1 acetate in the usual manner, or by the a dition of small amounts of amines. It has been shown that such compositions dry and harden upon standing to a resinous mass, and when spread on a surface exposed to the air form tough, resistantfilms.

The rate at which the films dry may be increased by the addition of driers such as soluble compounds of lead, cobalt and manganese. Because of the rapid absorption of oxygen by these synthetic drying oils, it has been found advantageous in some cases to add a small amount of an antioxidant, for example, eugenol, in order to reduce the tendency to skin and solidify in The amount of antioxidant.

Description of invention above described acetylene polymers and par-1 .ticularly, to increase their adhesive propertion is added to 4 ties and elasticity. Another object is the protection of objects exposed to the corrosive action of chemicals.

With these objects in view, a satisfactory method of modifying the above described liquid acetylene polymers, whether obtained directly from acetylene or further polymerized and subjected to distillation as described, has been discovered. It has been found that the product resulting from the action of sulfur chloride on these acetylene polymers produces a material which is softer, more elastic, and more adherent than the acetylene polymers not so treated. This sulfur chloride treated product may be used by itself or it may be used in connection, with softeners, res1ns,solvents and driers gas described above in connection with the unreacted synthetic dr ing oils.

11 order to disclose in detailthe preparation of the new coating compositions or synthetic drying oils, the following specific examples are furnished by way of illustration. It is to be understood, however, that it is not applicants intention to be limited to the particular conditions, proportions or reagents recited in the examples. I

Ewample 1 200 parts of an acetylene polymer product prepared from acetylene by passing the same into a mixture of ammonium chloride, water, cuprous chloride and copper powder is heat ed for 3 hours at 85 and the volatile constituents then distilled off to obtain 50 arts of a drying oil as described hereina ove. The 50 parts of synthetic drying oil are dissolved in an equal volume of toluene and then are treated with 1 part of sulfur chloride while undergoing agitation. When this material is applied to sanded steel strips and allowed to dry in the presence of air, a hard resistant film is obtained. The strip can "be bent at a sharp angle without danger of:

cracking or peeling.

\ Example 2 To the 50% solution of unreacted synthetic drying oil prepared from acetylene, as de scribed in Example 1, add a quantity of sulfur chloride in the proportion of 1 part by weight to 10 parts by weight ofthe acetylene polymers, while stirring to obtain a stock solution. When 1 part by weight of this soluparts by weight of the unreacted acetylene polymer drying oil, diluted with an equal weight of toluene, a coating protective film on the composition of similar properties to that described in Example 1 is obtained.

Example 3 parts of a liquid acetylene polymer of high molecular weight, obtained by heating an acetylene polymer comprisin divinylacet lane to about 85 for three ours and I Example 4 Divinylacetylene is heated for approximately 5 hours at a temperature of approximately 85 C. in the absence of air. The product is dilutedwith 2 volumes of acetone which causes a precipitate of tacky-rubber-like consistency to separate from the solution." This is separated by decantation and a portion dissolved in benzene, solvent naphtha, or other suitable solvent. The solution is then treated with sulfur chloride in amount equal to about 1 of the .weight of dissolved material. The dark viscous liquid is adapted for use as a coating composition.

Example 5 The coating composition as prepared in Example 2 is applied directly to pickled steel and allowed to dry. Two coats of the unrea'cted acetylene polymer drying oil are then applied. The resulting system when exposed to moist hydrogen chloride for 7 days remained intact. Steel coated with the untreated acetylene polymer and exposed under the same conditions was bady peeled.

with the system described above was exposed to alternate heating to 120 C. with steam or oil and cooling. After such exposure, the pot was found to be unaffected.

The coating system described above was applied to a cement floor. After 4 months'of exposure to shock, chemicals and abrasion, the floor was in good condition. Whereas, a floor coated with the untreated acetylene polymer drying oil and ex osed to the same conditions had stripped o in one month.

Example 6 Ten parts of unreacted synthetic drying oil prepared from acetylene, as described in Example 1, are mixed with thirty parts of an inert filler such as silica and ten parts of solvent naphtha; the mixture is treated with 110 An iron pot coated after sand blasting 1 one part of sulfur chloride while undergomg agitation. This mixture is applied as a base coat on the inside of an iron pot followed a coat of the synthetic drying oil described hereinabove and untreated with S Cl After allowing the coating to set and exposing it to the action of steam for 20 hours and thereafter treating the hardened coat with a carbon-tetrachloride solution of bromine. the pot ready for use. "Ihe brominationof an organic compound in nitro benzenesolution'may be carried out at 130 C.

. in fa ipot s'o qlinedx without corrosion acid'an, t ienzmay coating composition-directly or in c'ombinatiori'jwithvola- .It will be understood t eaaiaaaea ofthe-acetylene polymer-'with sul'fur chlo- -rideis not limited" to the-s ec'ific ropor- -tions or methods disclosed in Q 7.. Any one of the liquid acetylene poly-' mers, whether further polymerized or obtained directly from theacetylenerpolymerization, may be treated directly'iwithj sulfur chloride or they, or the solidsoluble polymers as well, may be first dissolved-insomelunreacted solvent, such as carbon tetrachloride or A benzene and thereafter treated". with, sulfur chloride. Alternatively, the sulfur chloride may be in solution in asol-v'ent for' thereaction product and the solution maybe added to the acetylene polymerwhficli -may' or may not be in' liquid state so long form. I p 5 1 To avoid a reaction with'ex the temperature must-be controlled during solvent in conjunction-with. coolingjins'ures ample control. 4 cooling in ice. I y-gbcco'me necessaryand the addition of sulfur' ch'lorid'e should-be" slow.

Also, the proportion of .si lfurchloride to the untreated acetylene polymer, may be varied. A liquid product adapted for use as a coating composition may beobtained by adding as high as 5% of sulfur chloride to a normallyliquid polymer in the absence of added solvent. A liquid of similar properties may be prepared by dissolving a soluble solid polymer or a normally liquid polymer in an added solvent for the reaction product and then treating with sulfur chloride. The concentration of the reaction product in such a liquid may obviously be controlled by the concentration of the polymer solution and by the quantity of sulfur chloride added andv are most by any ing the acetylene polymers with su ramp es 1 to 'isi'n soluble a solution of the desired A roperties and viscosity thus obtained for direct use. As hi h as 2 parts by weight of sulfur chloride or each part of acetylene'polymer may be added under these conditions. The degree to which the modification of the original unreacted acetylene polymer is carried. is determined by the amount of sulfur chloride added. It appears that the liquid products so obtained solid reaction product either in the unreact ed robably merely solutions of thei liquid polymers or the added solvent depend- 4 ing upon the method of their production.

The ultimateproducts obtained by saturatride possess essentially the same hysical properties irrespective of whether t e polymer so treated is the direct product obtained by the polymerization of acetylene or is the further polymerized acetylene polymer.

-Application of the coating compositions illustrated in the examples may be made by brush, spray, dipping or any other means adapted to insure a continuous surface. Ob-

viously, as many coatings of the material may be employed as are necessary to suit the specific conditions to which the equipment is to be subjected. Moreover, if desired, the protective coating may be finished by one or more coats of the unpigmented acetylene polymers described above.

The final drying and hardening of the'protective coatings may be accomplished in several ways: (1) the coating may be allowed to. slowly harden in the presence of air for several days at ordinary temperatures, 2) the ur chlohardening may be hastened by steaming or baking after the coating has set, or (3) it ma be treated, after it has set to a state in whic it will no longer register the impression of a thumb print, with agents which will react with the freshly deposited coat, such as oxyy gen, bromine, chlorine and others. p b 'vio enc Any finely divided inert substance, such as p v silica, graphite, barytes, etc., may be used as the coursegof thy-reaction.- "ThecuseQLofa I -.vent naphtha, toluene, xylene, etc., may be :Inithe absenceaof'ga solv'ent,

a filler. Inert volatile solvents, such as $01- erties are articularly noteworthy when the resulting lms are exposed to agents which tend to strip. crack, or blister and\ are therefore peculiarly adapted for treating chemical rine, bromine, iodine, acetic acid and otherorganic and inorganic acids, concentrated or in solution, except hot concentrated sulfuric acid and hydrofluorrc acid. They are unaffected by carbon disulfide, carbon tetrachloride,

aniline nitrobenzene,

toluene and phenol, benzene, chlorbenzene,

other or anic compounds. They will not withstan the corrosive action, however, of fused caustic. A hardened film of the new I composition has been found to give protecmore readily carried out than the ap lication a ainst the corrosive action resultin from t e phenylation of amino epsilon aci in aniline sulfate at 120; in the chlorination of anthraquinone sulfonic acid in which vitreous enamel has been found to fail; in the bromination of organic compounds in nitrobenzene at 130; in the reduction of compounds with metals in hydrochloric acid; and other chemical reactions of a corrosive na ture.

Moreover, the process of applying the new coating composition is less expensive and tion of the materials heretofore emp oyed for similar purposes. The protective coat mav be employed after the equipment is in stalled as well as before the installation which is not the case with vitreous enamel. Furthermore, linings of vitreous enamel cannot be repa red when damaged whereas the coating which is the subject of the present invention may be replaced in part or in its entirety as the need may arise.

As many apparent and widely different embod ments of this invention may be made without departing from the spirit thereof, it is to be understood that we do not limit ourselves tothe foregoing examples or description except as indicated in the following claims:

We claim:

1. The improvement in the art of protecting chemical equipment from the action of corrosive reagents which comprises applying thereto a film of a composition containing the reaction product of sulfur chloride with a liquid non-volatile polymerized nonbenzenoid acetylene polymer, said composition also containing a volatile solvent, allowing said film to set in the presence of air and thereafter treating it with an oxidizing agent of the class consisting of steam, oxygen, bromine and chlorine.

2. The process of protecting chemical equipment from corrosion which comprises applying thereto a film of a liquid conta ning a reaction product of not over 2 parts of sulsulfate fur chloride to substantially 1 part of a nonbenzenoid acetylene olymer, together with a. volatile solvent, al owing said film to set in the presence of air and thereafter treating it with an oxidizing agent of the class consisting of steam, oxygen, bromine and chlorine.

3. A process of protecting chemical equipment from corrosion which comprises applying thereto a film of a liquid resulting from reacting a solutt' on in an inert volatile solvent of a normally liquid non-volatile nonbenzenoid acetylene olymer with about 10% of sulfur chloride (based on the weight of the poliymer), allowing said coating to harden, an superimposing thereon a film having as its base a liquid non-volatile polymerized acetylene polymer and thereafter exposing said film to oxidizing conditions.

4. The process of claim 3 in which the final coat is allowed to set in the presence of air, thereafter steamed for 10 hours and finally treated with a solution of a bromine.

5. Chemical equipment provided with a coating resulting from applying thereto as a first coat a film of a composition comprising a liquid obtained by reactin 10 arts of a normally 1i uid non-volati e po ymerized nonbenzenoi acetylene olymer with about 1 part of sulfur chlori c, said composition also containing about 10 parts of a volatile selvent and 30 arts of an inert filler, allowing said film to arden, superimposing thereon a film of a liquid containing a non-volatile polymerized acetylene polymer and thereafter exposing said latter film to oxidizing condltions.

6. An article of manufacture, comprising a corrodible metal article havin thereon a protective coating, com rising t e oxidized reaction product of an fur chloride and a nonbenzenoid acetylene polymer.

7 An article of manufacture, comprising a a corrodible metal article having thereon a protective coating, obtained by applying to a surface of the said metal a liquid composition comprising the reaction product of sulfur chloride'and a nonbenzenoid acetylene polymer, allowing the film to harden and thereafter treating it with an oxidizing agent .of the class consisting of steam, oxygen, bromine and chlorine.

8. A hard resinous composition of matter comprising the oxidized reaction product of sulfur chloride and a normally liquid nonvolatile nonbenzenoid acetylene polymer.

9. A container for corrosive chemicals provided with a protective coating comprising the oxidized reaction product of sulfur chloride and a polymerized nonbenzenoid acetylene polymer.

10. Chemical equipment provided with a hard resinous coating comprising the oxidized reaction productof one part of a nonbenzenoid acetylene polymer with not over two parts of sulfur chloride.

11. A vessel for chemical reactions provided with a hard resinous (outing comprising the oxidized reaetion product of 10 parts of :1 normally liquid non-volatile polymerized nonbenzenoid acetylene polymer with about one part. of sulfur chloride.

In testimony whereof we afiix our signatures.

\VILLIAM S. EALCOT'I. ALBERT h. CARTER. FREDERICK B. DOWN-ING. 

